LEARN AFTER EFFECTS EXPRESSIONS For Beginners Tutorial

welcome back to another video my name is will and in this after effects video tutorial we're gonna be talking about expressions what they are what they can do and how they can improve your video work [Music] so what is an After Effects expression an aftereffect expression is a programming language made for After Effects similar to Java or HTML for building websites they can be very simple just a few characters in length or they can be extremely complex you can think of them like automated commands that perform specific actions within the layers of your After Effects composition when video editing it's common practice to use keyframes and while keyframes are very efficient and get the job done there are times when it would make much more sense to use an automated command so that you're not spending hours duplicating and creating keyframes so then how do you know when to use an expression and when to just use keyframes that completely depends on what you're trying to do it's always best to think about the end result and what you need to do in order to get there then decide if key framing will require more time or if creating expressions will require more time so now that you have a bit of an understanding I'll show you a few examples all right so with After Effects open let's go up to the rectangle tool I'll hold shift to make a perfect square and then with the Pan behind tool which also acts as the Anchor Point tool if you hold command on the Mac or control a PC and double-click it will reposition the anchor point to the middle of the shape so that when we rotate it it spins perfectly around the center point so command on the Mac control the PC then double click and that brought it to the middle and then down here let's open up transform we'll set a keyframe for rotation at our first frame and then we'll go to one second and twelve frames and we'll set this to one that means it'll do one full rotation between those keyframes so this is manually creating keyframes that we haven't made any expressions yet and then on the second keyframe I'm going to right-click it go to keyframe assistant and easy ease in so what that does is as it rotates it rotates it about the same speed but then as it gets to the second keyframe it slows down so it eases into the stop so if we wanted to have this infinitely loop throughout our composition of course we could duplicate the keyframes by selecting them copying and pasting them throughout our timeline a bunch of times but that is an inefficient way to work so a better way to do that is by using a loop expression so to do that on our shape layer we're gonna hold option on the Mac or alt on the PC and click on the stopwatch here on our rotation where our keyframes are that will open up the expression box and this is where we can enter in expressions let's type in loop and then we will select the loop out expression and hit enter so now we've created a loop and if we preview this you'll see what it says so even though there's no keyframes throughout the rest of our composition because we've set a loop expression it is looping the animation from the beginning throughout the rest of it so that's a pretty simple expression and it creates a really cool effect and for the loop expression keep in mind that it only works if you have keyframes on that layer all right so now let's start over with no expression and no keyframes now for a second example let's say we wanted our square shape to rotate continuously throughout our whole composition and we wanted to do that quickly and efficiently without creating keyframes the way to do that is once again option on the Mac or alt on the PC then click on the stopwatch for rotation and then in the expression box will type in time x 10 for example so what that's doing is for every second of time in the composition it'll rotate clockwise 10 degrees so if we go to one second here you'll see that it has turned clockwise ten degrees and if we wanted to make a go counterclockwise before the 10 we just simply put a minus sign so let's crank up the number to a higher amount let's say 50 so every second we'll go 50 degrees so that's what that looks like we've used no keyframes and just a few characters within the expression box to create a simple continuously rotating square shape now the power of expressions really shows when you have multiple layers with expressions so for example let's duplicate this layer we're going to transform and then under rotation will delete the expression from that layer and then on the rotation we will grab the pick whip and we will bring it to the rotation then when we go into the rotation you'll see that there is a longer expression and this may look intimidating however I'll explain what's going on here so what this expression is saying is on this composition for the layer shaped layer one which is this layer it's going to follow whatever the transform rotation does so I'm gonna go back to my main tool and then just move this over a bit and if I play this you'll see that both do the exact same thing and by doing it this way you don't need to write a whole bunch of apps reflects expression code you can just link the layers together and they'll work accordingly you can even take this a step further by going into the expression on our duplicated layer that has been pick whipped to the bottom layer and then at the end of the expression type space slash space - let's preview that so what this is doing is our first one is rotating at the same speed and our second one is rotating at half the speed so we divided it by two if we want to we go divided by four to exaggerate that a little more or we could even multiply it by let's say 15 to make the second one go much faster okay so moving on let's delete the top layer and then on our bottom one that is right now just spinning let's change this scale to 25 so it's a little smaller and then once again on the position stopwatch here we'll hit option on the Mac or alt on the PC then click and for this expression our goal is to have our shape randomly move around on screen so to do this will delete the transform position expression that's currently on it will type in WI and then we will select the fourth option which is wiggle and now we need to tell our expression how much to randomly move around our shape layer so the first value we will input is our speed so for this one let's put 2 and then we'll add a comma and then the next value is how many pixels on the screen it will move around so for this one let's do let's say 200 so it's randomly moving around the screen and you can see that it's creating a cool effect we still have the original expression which is the rotating at 50 degrees every second but this one is doing a movement of 200 pixels randomly at a speed of 2 also and the result we get is a really cool effect with 2 different expressions on the same shaped layer and if we were to try to do this with keyframes it would be a lot more difficult we'd have so many keyframes and it would just be a huge mess and this is a great example at how beneficial expressions can be and beyond that with the wiggle expression if we select it copy and then add it to the scale and then let's preview that and you can see what that does so it's flying around everywhere here so you can get really creative by mixing and matching different expressions expressions also work on footage as well so let's delete this I have a clip here of a tornado and the camera was locked off just sitting on top of a tripod so there's no movement but the scene is calling for some camera movement I think because it is a tornado it is a scary thing to see and to be close to so I think it would make a little more sense if there was some movement in the camera what we can do is add a fake camera movement so let's go into the clip and then we will add the wiggle expression again so this time we'll do a speed of 1 comma 25 so what that's going to do is going to have a slower speed and it's not going to move as many pixels and this will imitate more of a handheld feel but as you can see we're seeing some of the edges of the frame being revealed so we need to scale in just a little bit so let's say 105 and then we've created more of a handheld camera field from the static shot and you can play around with the numbers as well if you'd like if you think it should be a little faster we can go let's say 250 but keep in mind when you're using the wiggle effect on footage and you use larger numbers for the second number you will see more of the edges of the frame so you'll need to scale in more and that's not always a good thing because if you scale in too much you might introduce some noise into your footage so as you can see with just the wiggle effect alone you can get a lot of different results as another example this time let's go 30 for the first number and only 2 for the second one what this is gonna do is it's gonna be really fast movement but only going to be moving at 2 pixels so it's gonna look more like an earthquake so adding some very fast wiggle motion to your footage can help sell the effect all right so as I said in the intro of this video master effects expressions can be very simple but they can also be very complex so in this video we just touched the surface I talked you just a few expressions but there is so much more you can do ok so that's it for this video if you liked it hit the thumbs up leave a comment below subscribe and hit the bell to be notified when we release new videos we will see you next time [Music]

Channel: Alli and Will

Views: 7,996

Keywords: alli and will, video editing, content creator, will bartlett, alli saunders, cinematic, toronto youtuber, after effects tutorial, after effects expressions, ae expressions, after effects learn expressions, after effects basics, after effects expressions tutorial, adobe after effects tutorial, after effects camera shake, after effects motion graphics, video tutorial, video editing tutorial, after effects, motion graphics, how to, after effects tutorials, adobe after effects

Id: MaBIx0gQXec

Length: 10min 19sec (619 seconds)

Published: Thu Aug 15 2019

Reddit Comments

[u/AlliandWill]

This is a 10 minute video I made to help people just getting started with After Effects learn what expressions are and how to use them. I cover a few examples here and think it's a good starting point for beginners. If you already work with expressions, this post isn't for you :)

[u/Strottman]

Thanks for this, I've been meaning to get more into expressions beyond copy and pasting stuff I find on google.

[u/devine_111]

Saved! Thanks !!

[u/airsupply110]

really great tips